'Difficult' teens want family early, study finds

Teenagers who are more prone to aggression, delinquency, hyperactivity and school failure are more likely to want to start a family before 25.

However, the most academically gifted teens are keen to delay having children, with many wanting to wait until their 30s.

The findings are contained in a study of 1250 Australians aged 17 and 18 for the Australian Temperament Project, which is following children from infancy to adulthood to determine how temperament, family and environment can influence development.

The study shows that most of the teenagers thought the ideal time to have a first child was between 25 and 29. However, those with the most difficult temperaments more often wanted to start a family earlier.

"Perhaps they sense an opportunity for a fresh start," said Diana Smart, a research fellow at the Australian Institute of Family Studies.